Numerical investigations and optimizations of typical submerged box-type floating breakwaters using SPH

Box-type floating breakwaters have been studied extensively. However, the examinations of the performances of them with different shapes or different numbers of boxes are limited. In addition, if it is possible to optimize the floating breakwaters by combining the optimized parameters in separated testing groups is still unclear. Consequently, in this study, four typical box-type floating breakwaters, i.e., dual rectangular breakwater, single rectangular breakwater, dual circular breakwater, and single circular breakwater, are selected to do extensive investigations using SPH. The coupling between DualSPHysics and MoorDyn is implemented and verified, and the coupled code can be applied to simulate the interactions between waves and moored floating structures. A total of 88 cases are modeled, and the effects of the geometry parameters on wave-attenuation performances of the breakwaters are clarified. The numerical results show that the performances of the breakwaters are greatly sensitive to the immersion depth. In general, the larger and lighter the breakwaters, the better the performances will be. Meanwhile, the dual rectangular breakwater performs the best in wave attenuations, and its motions and forces are smaller than single breakwaters. Importantly, combining the optimized parameters in each separated testing group is found to be effective to optimize the floating breakwaters.